Running Hot And Cold: The Differences Between A One-Stage And A Two-Stage Heat Pump

14 August 2015
 Categories: , Blog


When asked if they know whether or not they have a one-stage or a two-stage heat pump in their central air/furnace at home, most consumers probably would not have a clue. In fact, this question is so technical, it ranks right up there with with questions about engine transmissions and drive shafts. To help clarify what these two types of heating pumps are and what they do, here is a little info on the differences between the two different types of pumps.

Heat Pumps Move Heat in or Out

Heat pumps are so named because instead of moving hot air from your home, cooling it and then reinjecting it back into your home via the air conditioner, a heat pump "pumps" the heat out entirely. Heat pumps also reverse this process by moving hot air from outside into your home (a more common practice in states where it is very warm during the day and very cold at night). The hot air pumped out or in sits in a "heat sink", waiting for a command from your thermostat to send the hot air where you want it to go (out or in).

One-Stage Heat Pumps

As the name suggests, one-stage heat pumps only move the heat from the source or heat sink in one direction. It is more commonly used to remove heat from a home, although it can be used to put heat back into the home. It just depends which use of the heat pump you prefer and which one the HVAC contractor installs.

Two-Stage Heat Pumps

An example of a two-stage heat pump is a reversible heat pump. You can set a two-stage heat pump to reverse hot and cold air in either direction--into or out of your home. A two-stage heat pump is highly recommended for states where winters are very cold, summers are very hot and your furnace has to work extra hard to heat and cool your home. Some of the best models of two-stage heat pumps are Trane heat pumps, which can also have varying speeds that allow for rapid heating and cooling.

Modern Heat Pumps

Regardless of whether you invest in a one-stage or two-stage heat pump, modern heat pumps on the high end can heat and cool within one-half degree. This level of energy efficiency makes them very popular with homeowners who are trying to cut heating and cooling costs. If you would like to invest in a heat pump system, talk to an HVAC contractor from a company like Cape Fear Air Conditioning & Heating Co., Inc.


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